Whenever a cellular structure, that is a structure composed by two vertical side walls and a horizontal floor is to be cast, tunnel like formworks are used composed by two vertical shuttering panels connected at their upper edges by a horizontal shuttering panel. The horizontal shuttering panel is normally supported by means of diagonal struts, fastened at one end to the lower side of the said upper shuttering, and at their other end to the vertical shuttering panels. Means are provided for adjusting the upper shuttering by means of the said struts. The vertical shutterings in turn are provided with adjustable bearing feet, and with wheels. When placing in operation the said frameworks, same are disposed side by side with the lower end of the vertical shuttering abutting against previously cast starter walls, and the vertical shutterings of adjacent formworks are connected together by means of suitable connecting wires.
The main disadvantages of the known tunnel-like formworks are that the operations requested for putting the said formworks into operation are time consuming and request a skilled workmanship.